If x² + y²+ 2x + 1 = 0, then the value of x³¹ + y³⁵ is

If a+b+c = 0 then the value of 

1/(a+b)(b+c) + 1/(b+c)(c+a) + 1/(c+a)(a+b) is

The simplified value of 

(1-2xy/x²+y²) ÷ (x³-y³/x-y - 3xy) is

A right circular cylinder having diameter 21 cm & height 38 cm is full of ice cream. The ice cream is to be filled in cones of height 12 cm and diameter 7 cm having a hemispherical shape on the top. The number of such cones to be filled with ice cream is

The diameter of a sphere is twice the diameter of another sphere. The surface area of the first sphere is equal to the volume of the second sphere. The magnitude of the radius of the fist sphere is

The lateral surface area of frustum of a right circular cone, if the area of its base is 16∏ cm² and the diameter of circular upper surface is 4 cm and slant height 6 cm, will be